Final answer:
To find the amount of water for one cup of concentrate, you would use 7.5 cups. For 10 cups of concentrate, you would use 75 cups of water.
Step-by-step explanation:
To find the amount of water Clare would use for one cup of concentrate, we need to set up a proportion. Since Clare uses 2 1/2 cups of water for 1/3 cup of concentrate, we can write:
2 1/2 cups / 1/3 cup = x cups / 1 cup
Cross multiplying, we get:
(2 1/2) * 1 cup = (1/3) * x cups
Simplifying, we get:
5/2 * 1 = 1/3 * x
5/2 = 1/3 * x
Multiplying both sides by 3:
(5/2) * 3 = x
x = 15/2 = 7.5
Therefore, Clare would use 7.5 cups of water for one cup of concentrate.
To find the amount of water she would use for 10 cups of concentrate, we can multiply the amount of water used for one cup (7.5 cups) by 10:
7.5 cups * 10 = 75 cups.